# Algebra 2 help: Going from standard form to vertex form?

• Jan 2nd 2013, 01:47 PM
wakefuldoze
Algebra 2 help: Going from standard form to vertex form?
Hey,

I'm having trouble figuring out this one problem and I need a little help.

The question is:

What is the vertex form of the equation?
y = x^2 - 2x + 8

the choices are:
a. y = (x+1)^2 + 7
b. y = (x+1)^2 - 7
c. y = (x-1)^2 + 7

How do you figure this out?

Brooke
• Jan 2nd 2013, 02:09 PM
skeeter
Re: Algebra 2 help: Going from standard form to vertex form?
Quote:

Originally Posted by wakefuldoze
Hey,

I'm having trouble figuring out this one problem and I need a little help.

The question is:

What is the vertex form of the equation?
y = x^2 - 2x + 8

the choices are:
a. y = (x+1)^2 + 7
b. y = (x+1)^2 - 7
c. y = (x-1)^2 + 7

How do you figure this out?

complete the square of the given quadratic function ... or expand the given choices and combine like terms.
• Jan 2nd 2013, 02:49 PM
wakefuldoze
Re: Algebra 2 help: Going from standard form to vertex form?
I did that but still got the wrong answer? Where am I going wrong?

I did this:

y = x2 - 2x + 8

(-2/2)2 = (-1)2 = 1

= (x2- 2x + 1) + 8 + 1

= (x-1)2 + 9

What did I do wrong??
• Jan 2nd 2013, 02:53 PM
skeeter
Re: Algebra 2 help: Going from standard form to vertex form?
Quote:

Originally Posted by wakefuldoze
I did that but still got the wrong answer? Where am I going wrong?

I did this:

y = x2 - 2x + 8

y = (x2- 2x + 1) + 8 - 1

...
• Jan 2nd 2013, 02:54 PM
wakefuldoze
Re: Algebra 2 help: Going from standard form to vertex form?
Oh I think I got it! Is it c?
• Jan 2nd 2013, 03:14 PM
wakefuldoze
Re: Algebra 2 help: Going from standard form to vertex form?
Well I am just going to go with that. Thanks for all your help.